Adds PyFx windlights and post process effects, not enabled by default.
Show custom graphics settings by default, because all our users are smart.
Tweaks SHAutoMask, uses Altocumulus as default cloud now
Added TODO into llrender/llpostprocess.cpp
We should also add the option to make the menu bar transparent, instead of pyfx using skin hacks
Also we need to add a settings preset feature at some point in the future.
We also need to add postproc to wlf.
Tweaked LLRenderTarget to support depth textures if FBO support is lacking.
Prefer LLRenderTarget::getFBO() over LLRenderTarget::sUseFBO when determining how to handle a specific LLRenderTarget object. (Decoupling to simplify logic without having to track a global)
